function imgChange(imgSrc,w,h,caption){
	var spaceW = spaceSize - w;
	var spaceH = spaceSize - h;
	var target = document.getElementById("bigimage");
	target.src = imgSrc;
	target.width = w;
	target.height = h;
	target.parentNode.style.width = w;
	target.parentNode.style.height = h;
	target.parentNode.style.paddingTop = Math.floor(spaceH / 2);
	target.parentNode.style.paddingBottom = Math.ceil(spaceH / 2);
	target.parentNode.style.paddingLeft = Math.floor(spaceW / 2);
	target.parentNode.style.paddingRight = Math.ceil(spaceW / 2);
	document.getElementById("file-caption").innerHTML = caption;
}